Tire/Rim question

Not sure if this was the right forum so I apologize in advance if its not. I have 18’s on my car right now that have 225/40 tires on them. My stock 16’s weigh about the same as my 18’s I believe. My 16" wheels are 6.5" wide and my 18’s are 7.5" Wide. Now which would be better for the track? I know the 18" wheels have a greater rotational mass but they’re also wider so maybe better for traction? I’m going to try and find a wider 16" wheel to put some good tires on once I start spraying but for now I’m going to use what I have. Thanks guys


What kind of track? Drag racing track? Road Racing Track?

Sounds like drag racing to me. You dont spray on road courses, and you dont usually worry about straight line acceleration (I garuntee he isnt talking about lateral).

For what kind of track?

Assuming 225s in both cases (16/18).

The 16s would be better for drag racing, and road course. The wheel width is really neglegible for a 225.

Not only are 18’s heavier, but the mass is farther from the center, causing a greater moment of inertia. In the case of road course/auto-x, I’ve seen 225s mounted on 5.5" wide rims. Not idea, but it does work.

For a soft sidewall street tire, there may be more performance with the taller rim in twisties. Just because they will probably need a lower aspect ratio to maintain the same rolling diameter. Lower aspect ratio = stiffer side wall = higher slip ratios = higher lateral loading per given smaller slip angle (to a point).

Yeah sorry its for 1/4 mile racing. Now that my wife is working I have money again to start modding my car and since all my toys are on the way I need to go get a baseline run in and am trying to decide which rims I should have on my car.